214 A. CONTBIBTJTION TO, EtC. 



natural history and woods of the colony. The first method by 

 which botanists proposed to divide the genus into sections, was by 

 measuring the length of the operculum or lid of the flower-buds, 

 so that all species having the lid longer than the cupula or cup, 

 were placed in the first section : those that have the operculum 

 conical and equal in length to the cupula, were referred to the 

 second ; whilst the third section contained such species as have 

 the operculum nearly conical, or hemispherical, and shorter than 

 the cupula. To these sections were added two more divisions, in 

 one of which, the operculum was to be hemispherical, much 

 broader than the cupula, and in the other, the mature operculum 

 was depressed in the centre, where it is umbonate and shorter 

 than the cupula. But this artificial arrangement is not only 

 defective, from the fact that the operculum, even in the same 

 species, is not always of the same shape and size, as might be shown 

 from specimens of the grey gum (E. tereticornis) and the droop- 

 ing gum (E. saligna), but it is also open to the serious objection 

 of separating species which, by every other mark, are nearly 

 allied. Thus, for instance, all the ironbarks, mahoganies, and 

 common gums should be arranged near to each other in respective 

 sections, being not merely similar in bark, the nature of their 

 wood and general habit, but also in the character of their inflores- 

 cence and seed vessels. And yet, if the did system be fairly 

 carried out, we should be compelled to place some allied species 

 in one section, and some in another, thus destroying the simplicity 

 which would arise from judicious grouping, and in fact throwing 

 the whole genus into inextricable confusion. I believe that this 

 inconsistency has been the cause of much difficulty to persons 

 studying the genus, and has induced some to give it up in despair, 

 for although the comparative length of the operculum, as well as 

 its shape, may be a guide in determining those species which are 

 uniform in that organ, yet the irregularity which prevails in the 

 opercula of other species must lead to perplexity, especially when 

 the student is relying upon dried specimens without any know- 

 ledge of the tree in a living state. Seeing, therefore, that there 

 is no advantage in trusting to an artificial system, which is neither 

 uniform in its results, nor designed to connect allied species, Dr. 

 F. Mueller, in a paper read before the Linnean Society, in 1858, 

 suggested the expediency of grouping the species according to 



